1. Technical Field
This invention relates to a sling such as a chain sling, a wire sling or a belt sling and, more particularly, to a sling suitably used to support or raise a drum and the like.
2. Description of the Prior Art
In the slinging work of drums and the like, chain slings and similar slings have been widely used. A typical type of chain sling has a master link 1 to be hooked by a lower hook of a lifting machine such as a crane or a chain block, hooks 3 to be clamped onto a drum 2 and link chains 4 connecting between the master link 1 and the hooks 3, as shown in FIG. 26.
Each hook 3 comprises a hook body 5 having an upper portion of a hooked shape and a lower portion of a generally L-shape and a grip portion 6 of a hooked shape which is swingably mounted at the upper portion of he hook body 5. When the drum 2 is held by the sling, the hook bodies 5 are put into abutment with side portions of the drum 2 at front ends of the generally L-shaped lower portions thereof and also clamp a ring-like protruding portion of the drum 2, at which an upper lid 7 closing an upper opening of the drum 2 is mounted, by rear ends of the hooked-shaped upper portions and the grip portions 6.
The master link 1 has curved lower portions and connecting portions 8 projecting downwardly from the lower portions so as to be connected with the link chains. The connecting portions 8 have insertion holes formed along a plane containing a direction orthogonal to a plane containing the master link 1. Inserted in the insertion holes are support shafts 9, on which upper ends of the link chains 4 are supported.
This conventional type of chain sling has the disadvantage of being unable to raise the drum 2 which is varied by, for example, cutting it in half, after the upper lid 7 of the drum 2 is opened, so that only the lower half can be used as a container. This is because the drum no longer has the ring-like protrusion portion at which the upper lid 7 is mounted and has no parts to be clamped in sandwich relation between the rear ends of the upper portions and the grip portions 6 of the hook bodies 5.
Also, the master link 1 is usually raised by a crane or a chain block but sometimes is raised by a forklift and the like. In the latter case, the conventional arrangement of the connecting portions 8 being formed to project downwardly from the lower portion of the master link 1 has the disadvantage that the downwardly projecting connecting portions 8 abut with a lifting portion of the forklift to hinder a stable support of the master link 1.
It is the object of the present invention to provide a sling capable to easily raise a hanging load such as a drum with a simplified structure.
The present invention is directed to a novel sling comprising a master link, hooks and flexible string-like members for connecting between said master link and said hooks, wherein lower portions of the hooks are formed to be bent at an angle smaller than 90xc2x0.
With this construction, since the lower portions of the hooks are bent at an angle smaller than 90xc2x0, for example if the drum with no protrusion to be hooked is provided, around its side surface, with holes to insert therein the front ends of the hooks, then the front ends of the hook can reliably be hooked in the inside of the drum. Thus, the sling of the present invention has the capability to reliably hold the drum with the hooks even when an upper lid is opened and the drum has no protrusion, thus ensuring the good raising work.
According to the present invention, in the sling in which the master link and the hooks are connected with each other with flexible string-like members, a flat portion is formed on at least a part of a bottom of the master link.
With this arrangement, since the flat portion is formed on the bottom of the master link, for example when a lifting portion of the forklift is inserted and is abutted with the flat portion of the master link, the master link can then be stably supported by the lifting portion. Thus, the chain sling of the present invention can be used with the forklift as well as the crane and chain block with ease and reliability to raise the drum.
In this embodiment, it is preferable that connecting portions to be connected with the flexible string-like members are formed in the master link at places above the flat portions.
With the arrangement in which the connecting portions are formed at places above the flat portions, when the master link is raised by the forklift, the lifting portion of the forklift is surely brought into contact with the flat portion of the master link without contacting with the connecting portions. Due to this, the master link can be raised further reliably even by the forklift.
It is preferable that the connecting portions have insertion holes formed along a plane containing the master link, and the flexible string-like members are supported by support shafts inserted in the insertion holes.
With the arrangement in which the insertion holes are formed along a plane containing the master link, the simple machining work of the insertion holes and the reliable support of the flexible string-like members can be yielded, as compared with the arrangement of the insertion holes being formed along, for example, a plane containing a direction orthogonal to a plane containing the master link. In addition, the replacement of the support shafts can be facilitated.